It is actually not a reliability issue with Google Nexus 5, but attackers have found a way to reboot or failed to connect to internet error after sending massive flash sms messages. When someone spam you with over 30 Flash messages, your Google Nexus phone may act weird.
According to PCWorld, the issue was detected by Bogdan Alecu. Bogdan is a system admin at Dutch IT Company Levi9. This issue is with all the line-up of Google Nexus series and Android 4.x, including Google Nexus 4 and 5. Bogdan Alecu will present this security issue in DefCamp security conference in Bucharest, Romania.
Flash SMS or Class 0 sms is a special type of SMS that isn’t stored on phone memory. It is only displayed on user screen and disappear when you press the back button or save it.
Google Nexus phone display the message on top of everything. It has dimming effect on sides and when another message is received the dimming effect increase. There is no SMS alert tone or vibration for Flash messages. User does not know when they receive such messages. Alecu discovered that when you receive over 30 Flash messages, Google Nexus phones starting to act abnormally.
You may experience phone reboot and phone may not connect to the network. According to Alecu, users may not be able receive calls or sms because you might not notice the problem.
Another issue highlighted is that your phone will not reboot and temporary loose the connection to the cellular network. It will be restored after a while, but you won’t be able to connect to the internet.
A live test was performed with Google Nexus 4 and with over 30 Flash messages, phone wasn’t able to receive calls. You have to reboot it manually to make it work.
Alecu claimed that he found this issue over a year ago and tested on various Google Nexus series phones. He also tested 20 other phones from different vendors, but they were not vulnerable to this problem.
Should you buy Google Nexus Phones?
According to our test on Google Nexus 4 and Google Nexus 5, we did not faced such issue on receiving 15 Flash messages. We are not sure who on earth would spam with you over 30 Flash messages? Maybe a kid or college students trying to annoy you.
Moreover, Flash messages are hardly used these days. Sometimes, mobile carriers send promotions via Flash messages, but it is very unlikely that you will not notice receiving over 30 messages.
It is safe to use Google Nexus phones and there are not much threat as long as you don’t spam your phone with flash messages. According to PCWorld, they are waiting for official Google response on the issue.